1. Field of the Invention
The disclosure herein relates generally to the field of subterranean hydrocarbon production. More specifically the present invention relates to a system for facilitating desired orientation of a downhole string.
2. Description of Related Art
Many downhole tools, including perforating guns, comprise multiple elongated bodies joined end to end. If the elongated bodies are to be rotated or axially positioned, the elongated bodies must be able to rotate freely with respect to the adjacent body or bodies they are connected to. When a downhole tool is inserted within a deviated wellbore, gravity and other forces causes friction. Free rotation of the elongated bodies of a downhole tool is then hindered. If free rotation of the elongated bodies is hindered, they will not be able to be positioned into the desired orientation. Therefore, when the downhole tool consists of multiple perforating guns, perforations cannot be produced at the desired orientation along the wellbore.
When perforating guns, are used in slanted or deviated wellbores it is often important that the tool be in a specific radial orientation. For example, orienting perforating guns in deviated wells enables the well operator to aim the shaped charges of the perforating gun at specific radial locations along the circumference of the wellbore. This is desired because the potential oil and gas producing zones of each specific well could exist at any radial position or region along the wellbore circumference. Based on the presence and location of these potential producing zones adjacent a deviated well, a well operator can discern a perforating gun orientation whose resulting perforations result in a maximum hydrocarbon production. Not only could a perforation aimed at the wrong angle not result in a preferred hydrocarbon production, but instead could produce unwanted sand production from the surrounding formation into the wellbore.